Well-drilling tool



Patented Nov. 11, 1930 PATENT oFFicE CHARLES E. BRINTON, OF LOS ANGELES, CALIFORNIA WELL-DRILLING TOOL Application filed March '31, 1926. Serial No. 98,641.

This invention relates to improvements in well drilling tool, and refers more particularly to a novel construction of well drilling tool, comprising an inner conduit and an outer casing therefor, in combination with sealing elements having sealing contact with the inner wall of the outer casing andouter wall of the inner conduit to provide buoyant chambers. n

In the drilling of oil wells, for instance,

the drilled hole is kept constantly filled with fluid mud. In some instances, this mud is quite thin, and in other instances, where for instance, the formation is loose or inclined to cave, the mud is maintained in a very thick condition. This practice is well known and is usual in oil well drilling. This mud, together with such water as is needed in the hole, is'pumped down through the pipe forming the tool string or casing, and is ejected through the bit at the bottom of the tool string. The hole in the bit through which such mud and wateris ejected, ranges from a quarter to say, an inch in diameter,

whereas the hollow pipe forming the tool string or casing is many times the diameter of the hole in the bit, for instance, from 6 to 12 inches. mud and water is forced downwardly through a 6 to 12 inch pipe, and is ejected from the bit through an outlet which is very small relative to the casing. The volume of mud. or water contained in the casing has been found not only unnecessary, but it representsan ever-increasing weight as the well is deepened; probably averaging about 5 tons increase for each 1,000 feet. One of the main objects of the present invention is to reduce the volume of mud and water used, thus ,materially reducing the increase in weight due to the large volume of mud and water now maintained. An-.,

other important objectof the invention includes the reduction in weight of the tool strings or casing used in drilling operations. By the present invention, it will be possible to facilltate the drilling of deeper holes than is now possible and also materially reduce the difliculty and expense of drilling shallow wells.

It will thus be seen that the' The two above objects, and many others which will be hereinafter more specifically brought out are accomplished by the present invention in a novel manner. The buoyancy chambers heretofore described, may be filled with air or other gaseous medium and being sealed against accidental loss of air, will become so buoyant, that they will in effect neutralize the weight of the adjacent casing. The fundamental principle of air buoyancy is so thoroughly understood, that it is not deemed necessary to enter into an exhaustive discussion.

In the drawings, Fig. 1 is a vertical cross sectional view of an oil well drilling tool embodying the present invention.

Fi 2 is an enlarged crosssectional view showing a connection between two lengths of the tool string or casing.

,Fig; 3 is a cross sectional view taken on line 33 of Fig. 2. k

Fig. 4 isa View s i M slightly modified form of construction.

Referring more particularly to the drawings, 1 designates a length of steel tubing having a diameter between say '5 and 12 inches, which will hereinafter be referred to as the outer casing." The outer casing may be manufactured in standard 20 foot lengths and is provided at both ends with external screw-threads 2 adapted to register withthe screw-threaded collar or joint 3, which connects two joints or lengths of casing 1. The lower end of the lowest casing in the hole-4 may be provided with a suitable reinforced portion 5 and internally screwthreaded as shown at 6 to register witlrthe icre yzv-tlireads opthe'pin end of a drilling it I have illustrated and I shall describe the present invention asbeing applied to the rotary type of drilling tools. it is to be understood of course, that the invention is apin diameter and cross sectional area than the outer casing 1. This inner conduit 8 may be milar to Fig. 1, of a J manufactured in standard 20 foot lengths having any suitable joining connection at 9.

a This inner conduit 8 of reduced cross sectional diameter is adapted to receive the mud and water, delivering same from the lowermost onduit 8 through the aperture 10 onto the face of the bit. It will be thus instantly obvious that there is maintained in the lengths of I inner tubing 8 only a relatively small-volume 10 of mud and water, which, of course, materially reduces the weight of the inner string of tools normally imposed on the derrick. This is one of the important features of the present invention. I As another feature of the present invention, in each length of easing or' in certain predetermined lengths, there are provided spaced. disks or sealing elements 11, having sealing contact and surrounding the inner go condu7t 8 andhaving sealing contact with the innerwall of the outer casing 1. Thus, there is provided in certain or all ofthe lengths of easing 1 seal buoyant chambers A. There may be any n mber of these chambers in each casing, and these chambers'may be formed inany or all lengths'of the casing. It is obvious that otherse'aling means than the disk 11 may be utilized.

For'the purpose of introducing a buoyancy creating medium, such as air or other gaseous medium which is introduced under pressure to each chamber A,I provide an inlet designated as a whole 12, which comprises an externally screw-threaded valve 13, having a restricted inlet 14, which inlet is normally closed by the ball or other closure element 15' held against its seat by the coil spring 16 anchored in the removable cap 17, which cap is also apert'ured at 18. This arrang ment 40 allows the buoyancy-creating medium 0 be readily introduced to the chamber, but prevents any accidental escape of air or gas from the chamber A.

For the purpose of illustration, the pipe 8 may be from say 1- to 2 inches in diameter and the casing '1 may be from say;6 to 12 inches in diameter. This inner conduit 8 mafy be welded into fixed position by means 0 the sealing elements 11, if desired The intakevalves 12 ma be positioned in one or both of the sealing 'sks, 11. The cubic area of the buoyancy chambers A will depend, of course, upon the dimensions ofpipe used, and the pressure maintained on the buoyancy creat- 56 ing-medium therein-may be regulated at will.

) 'In assembling, 'as each length of casing is joined to the one below, air or gas may be introduced through the intake valve tothe desired quantity. In operation, it will be .become. Referring more'Fparticularl 'fication shown; in 1 .4, it wi be noted that every other joint 0 the casing is provided with what is known commercially as a tool 1 wall instead of placing it in the disk.

The \sealing' arrangement in Fig. 4 comprises the disk 11 welded to the wall of the casing and also to the small mud pipe 8 and adjustable disk 22, between which is adapted to be interposed 'a flexible gasket 23, the arrangement eing such that-I compensate for difference in expansion and contraction'between the line 8 and the casing 1. The adjustable disk 22 may screw onto the lower end of each joint of pipe 8.

I claim as my invention:

1. A well drilling tool, including in combinati on outer and inner conduits, said inner in certain instances, to place the valve in the conduit being spaced from the wall of the outer conduit, sealing elements surrounding the inner conduit and having sealed contact with the inner wall of the outer conduit longi- ,tudinally inwardly of its ends to form sealed -buoyant chambers containing gas and means carried by some of the sealing elements for introducing a buoyancy creating gas to said chambers. v

2. A well drilling tool, including in combination a closedinner conduit and an enlarged casing surrounding same, said conduit and easing each comprising intercoupled sections with the couplings for. the same occurring at substantially the same points, 5

sealing disks surrounding the endportlons of each section of the closed inner conduit and having sealing contact with the inner wall of the outer casmgjto form air chambers and means carried by the'upper disk for eac sec-- tion of the conduit forintroducing air to said chambers.

3. Awell drilling tool, including in com-.

bination a closed inner conduit and an enlarged casin g surrounding same throughout its length, sealing disks 'surrounding the closed inner conduit and having sealingcontact with the inner wall of the outer casing longitudinally inwardly of its ends to form air chambers, and valves insaid disks for introducing air to said chambers.

to the modi I I CHARLES; E. BRINTQN." 

